Air-cooling means for internal-combustion engines



May 22, 1928.

A. G. M. MICHELL AIR COOLING MEANS FOR INTERNAL COMBUSTION ENGINES FiledSent. 20. 1927 2 Sheets-Sheet l May 22, 192s. 1,670,666

A. G. M. MICHELL AIR COOLING MEANS FOR INTERNAL COMBUSTION ENGINES FiledSept. 20.l 1927 2 Sheets-Sheet 2 Patented May 22, 1928.

UNITED STATES PATENT OFFICE.

ANTHONY GEORGE MALDON MICHELL, OF MELBOURNE, VICTORIA, AUSTRALIA., AS- lSIGNOR To cRANKLEss ENGINES LIMITED, E MELBOURNE, AUSTRALIA.

.AIR-COOLING MEANS FOR INTERNAL-COMBUSTION ENGINES.

Application filed September 20, 1927, Serial No. 220,762, and in GreatBritain July 27, 1926.

The object of the present invention is the provision .of more effectiveand efficient alroooling means for the cylinders of internal fcombustion engines of the type in which the result of its own passagethrough the air when mounted in a flying-machine or other vehicle, butthe invention is also in part ap plicable to stationary engines.

It is in many cases desirable to arrange the working cylinders ofcrankless engines at the rear as well as the front of the main case ofthe engine, or sometimes at the rear only. It is to the cooling of suchrear cylinders that the present invention, which consists in improvedcooling apparatus, Yis particularly directed.

According to the present invention, the air meeting the front (orWindward end) of the engine and being thereby deflected outwardly isintercepted by an annular series of baf fles 0r a collector plate ofsuch shape and arrangement that parallel' air streams are formed, suchparallel streams being subsequently intercepted by an annular series ofbaffles at the leeward end of the engine and of such shape andarrangement that the parallel air streams are diverted inwardly upon andover the vrear cylinders. The baffles may be arranged in stepped annularformation. The baflle or collector plate may be of annular orcylindrical shape, its` rear being apertured centrally. A fan may beprovided at or near the exit. from said collector or baffle plate.

In theaccompanying drawings, the inven* tion is shown in. Figs. 1 to 3,5, 7 and 8, as

applied to engines of flying machines; Figs.'

1 to 3 and 5 being diagrammatic, while Figs. 7 and 8 are longitudinaland end views re! spectively of a practical form of construction of an'engine and the -cooling device as shown diagrammatically, in Fig. 2.Fig. 4 is a diagrammatic view showing the application of the inventionto a stationary engine. Fig. 6 is a diagrammatic view of a. cranklessengine for flying machines without the cooling device.

In each of the Figures 1, 2, '3, 5 and 6, the engine shown by way ofillustration, is a crankless engine a'daptedto be propelled togetherwith its support, through the air by means of a propeller P mounted atthe front of the engine.

Figures 1, 3, 5 and 6 represent single-end ed engines, that is to sayengines having their working cylinders C mounted only on the rear endsof their castings or bodies B.

For convenience of explanation of the improved cooling apparatus theengine will be regarded as at rest, as is the case of theV cranklessengine in Figure 4, and the air as moving in the direction shown by thearrows a and so that the air has thus the same motion relative to theengine as if the latter were travelling forward in still air.

In an engine unprovided with the cooling apparatus which forms thesubject of the present invention, air streams meeting the front orWindward end ofthe body B tend to be deflected laterally away from theengine, as indicated in Figure 6, and `to diverge more and more as theyprogress to- Wards the rear, as shown at a', a, in that figure. The airsurrounding the cylinders C is in consequence either stagnant, or, atthe most, disturbed only by secondary eddies e eas indicated in Figure6, and. has consequently little cooling effect.

According 'to the present invention, and as shown in Figures 1, 2, 3, 4and 7, air is intercepted by an angular' series of baffles L1 arrangedaround the front circumference of the body B. Alternatively, acylindrical baf-l lie or collector K may be provided for the samepurpose yas shown in Figure 5.

The baffles are of stream-line forms and are designed to deflect the airwith as little loss of energy as possible into paths 7) b approximatelyparallel to the axis of the yengine, a second annular series of baffleslL2 is arranged, these being located so as to deflect the airstreams bI) inwardly over and between 'the cylinders and designed, like thebafHes L1, to deflect the air with the least possible loss of energy.

In the double-ended engine shown in Figure 2, in which cylinders C1 aremounted at the front end as well as the cylinders C2 at the rear end ofthe engine body B, the air streams aa are deflected outwards partly bythe front cylinders, which they serve to cool, and partly by the frontof the body B, as in the arrangement illustrated in Figure 1.

The series of front bafflesL1 is therefore distributed over a greateraxial distance than in Figure 1 so as to intercept as far as possible ,ythe variousl streams diverging from both the body B and the cylindersC1. In other respects the construction and effects in the arrangement ofFigure 2 are similar to those of Figure 1. In both the single anddouble-ended constructions, annularl or sectional baffles F may beadded, continued by cylindrical extensions outside the leeward louvres,as indicated in Figs. 2 and 7, to intercept additional air and/or toconcentrate the flow of air about the cylinder heads.

The construction shown in Figure 3 is precisely the same as that ofFigure 1, except that a fan G isfmountcd at the rear end of the engine,upon, or co-axially'with, and driven by the engine shaft so as toreceive the airstream issuing from between the cylinders, and by itspropelling or tractive action upon the air, increase the fiow andcooling effect of the current. In order to prevent air from being drawndirectly into the inlet of the fan G without passing over and coolingthe cylinders C an annular baie H may be fitted,

thisbafile beingalso continued outside the leeward louvres, as shown.

A practical mode of construction' of the baffles above described andtheir attachment to the engine, is illustrated in Figs. 7 and 8.According to these figures the baffles L1 and L2 are continuous rings,of stream like section, preferably of a light alloy, smoothly machined,arranged concentrically and attached to one another and to the-engine byoblique radial bracket-arms M,L M2.

The annular baffle F, is preferably spun from sheet metal and beingconcentric ywith the baffles L2 may also be attached withv them to theengine by the arms M2.

In the double-ended engine representedin Figure ,4, and operating as astationary engine, the fan G alone produces the propelling effect uponthe cooling-air. In order to prevent the fan from drawing. air directlyinto its inlet Without such air passing between the bafiies L1 and L2and over the cylinders, the bailcs are surrounded by a cylindricalbaiiie or collector J. The construction and eect of the cooling means inthis case are similar to those shown in Figure 2 except for the additionofthe fan G, and the increased length of the cylindrical portion of thebaille J in 4 Figure 4 as compared with the baille F in Figure 2. It isto be understood that these modifications are also applicable to adoubleended engine when fitted with a propeller, as shown in Figure 2,and used as the engine of a flying machine.

The sets of baffles L1 and L2 are prefer-I the leeward end of the engineto intercept said parallel air streams and divert them inf wardly uponand over the rear cylinders.

2. The combinationv with an internal combustion engine, in which theworking cylinders are cooled by a current of air iowing parallel to theaxis of the engine, 0f a series of annular baffles arranged in steppedformation for deiecting said current of air inwardly upon and betweenthe engine cylinders situated at the leeward end of the en-I gine.

ternal combustion cra-nkless engine, of a series of annular balesarranged around the Windward end of the engine, a series of annularbafiies arrangedvaround the leeward end of the engine, and a centrallyapertured annular baffle surrounding the leeward bales.

Dated this 24th day of August, 1927. e. ANTHNY GEORGE MALDONMlCl-IILI..y

3. The combination with an air-cooled ini

